Download 2008 (Bba_K112808). By the help of our model, we can conclude

Berke Gürkan, Özge Özgüç, Ekin Sağlıcan, Gözde Arabacı, Melike Dönertaş, Buse İşbilir, Kübra Narcı, Alişan Kayabölen, Özgün Kırdar, Emre İlpars, Burak
Özcan, Side Selin Su Yirmibeşoğlu, Oğuz Bolgi, Seda Koyuncu, Hasan Fehmi Danacı
Advisors: Ahmet Çağlar Özketen,T aylan Beyaztaş, Gökhan Ersoy
Instructors: Mahinur S. Akkaya and Zelha Nil
INTRODUCTION:
Carbon monoxide (CO) poisoning is one of the most harmful types of air
poisoning in the world. CO gas is mostly released from the internal
combustion of engines as well as the use of fuels such as wood and coal.
Since carbon monoxide is colorless and odorless it is very hard to be
detected without using technological means. However, an enzyme called
Carbon Monoxide Dehydrogenase (CODH), found in Mycobacterium
bovis, is able to convert CO gas into CO2 gas chemically. In this project, we
tried to build a system which can act as a CO filter which can be used to
reduce the amount of CO gas in areas where it is elevated. We also
attempted to introduce two systems that will help for safer and more
controlled use of our “eCO Filter”
CARBON MONOXIDE CONVERTER:
CODH enzyme that we used in our system is
isolated from Mycobacterium bovis. This
enzyme is able to convert both CO into CO2
and CO2 into CO depending on their
concentrations.
The action mechanism of the
enzyme is not yet very well studied
so it is not possible to gather very
good data on its mechanism, yet
the procedure is as in the drawing
on the right. By using this enzyme
the amount of CO can be reduced.
KILL SWITCH:
CELL LIMITER:
We built a kill switch by modifying the T4 lysis device designed by Berkeley
2008 (Bba_K112808).
Our kill switch is designed to enhance
safety for biological machinery to be
used by many, outside the laboratory.
The design allows the growth of
bacteria only when there is IPTG
available. When the bacteria used if at all escapes from its designated area
(which contains IPTG ) It will not be able to have excess to IPTG in the system
via diffusion. When the free Holin molecules reach 3000[ref] cell lysis will
occur.
We also have a model of our system.
By the help of our model, we can
conclude that when there is no IPTG
molecule, cell lysis occur in 275
seconds. However, in the presence of
100000 IPTG molecules, cell needs
2290 seconds to lyse. As it can be
seen in the graph ,until a very high
IPTG concentration such as Run14,
the increase in Holin can eventually
cause lysis. As a result of our model ,
we concluded that after an IPTG
concentration of 700000 molecule s,
the cell lysis will not occur. In the
graph, Holin molecule s are
represented with red curve .
Cell population density changes as the bacteria grow and
divide in the biofilm and QS can be defined as the regulation
of gene expression during this change. As the cell density
increases bacteria starts to release molecules named as
autoinducers and according to the concentration of
autoinducers gene expression is altered. Eventually bacterial
growth will be controlled. In our project , we aimed to modify
E.coli to synthesize its own QS signals, detect the cell density
and prevent the cell division. When 3OC6HSL is produced, it
will form a complex with LuxR which is synthesized according
to the activity of LuxPL promoter. After that point we aimed
LuxR-3OC6HSL complex to increase the activity of LuxPR
promoter. Finally LuxPR activity determines the amount
of LasR and when PLasR
promoter is activated MinC,
a cell division inhibitor can
be synthesized. Eventually,
cell division stops after
MinC reaches its critical
concentration.